In the conventional computer system, a mouse device is widely used to control a cursor position or a page scrolling action of a display screen of the computer system. In the conventional mouse device, an upper cover is usually divided into a left button zone and a right button zone. When the left button zone or the right button zone is pressed down, a corresponding switch on a circuit board is triggered. However, since the upper cover of the conventional mouse device is divided into the left button zone and the right button zone, a seam is formed at a middle region of the upper cover. Under this circumstance, the integrity of the entire outer appearance of the mouse device is restricted and destroyed. In addition, the use of the conventional mouse device is limited. For most users, since the index finger and the middle finger are frequently placed on the left button zone and the right button zone, respectively, the design of the conventional mouse device is detrimental to the hand care of the user. Moreover, due to the above limitations, the conventional mouse device fails to provide a multi-touch function.
For solving the above drawbacks, a key-free mouse has been disclosed in U.S. Pat. No. 7,164,412 for example. Hereinafter, the structure of the key-free mouse will be illustrated with reference to FIG. 1. FIG. 1 is a schematic exploded view illustrating a conventional key-free mouse.
First of all, the components of the mouse device 1 will be illustrated. The mouse device 1 comprises an upper cover 10, a lower cover 11, and a circuit board 12. The upper cover 10 comprises two pivotal shafts 101 and two pressing parts 102. The two pivotal shafts 101 are located at a front side and a rear side of the upper cover 10, respectively. The two pressing parts 102 are located at a left side and a right side of the upper cover 10, respectively. The lower cover 11 comprises two fastening slots 111. The two fastening slots 111 are located at a front side and a rear side of the lower cover 11, respectively. Moreover, the mouse device 1 further comprises two springs 13, a first switch 14, and a second switch 15. The first switch 14 and the second switch 15 are disposed on a top surface of the circuit board 12. The two springs 13 are disposed on the first switch 14 and the second switch 15, respectively.
For assembling the mouse device 1, the circuit board 12 is firstly disposed on the lower cover 11. The upper cover 10 is connected with the lower cover 11 from the top side of the circuit board 12. Moreover, the two pivotal shafts 101 are inserted into the two fastening slots 111, respectively. Consequently, the upper cover 10 is rotatable relative to the lower cover 11. In addition, after the upper cover 10 is connected with the lower cover 11, the first switch 14 and the second switch 15 are disposed under the two pressing parts 102, respectively. Moreover, the two pressing parts 102 are connected with the two springs 13, respectively.
When a left side of the upper cover 10 of the mouse device 1 (i.e. the left side of the right-handed user who operates the mouse device 1) or a right side of the upper cover 10 of the mouse device 1 (i.e. the right side of the right-handed user who operates the mouse device 1) is depressed by the user, the upper cover 10 is rotated relative to the lower cover 11. As the upper cover 10 is rotated relative to the lower cover 11, a corresponding pressing part 102 of the two pressing parts 102 is moved downwardly to push a contact part 141 of the first switch 14 or a contact part 151 of the second switch 15. Consequently, a corresponding command is executed by the computer.
When the left side or the right side of the upper cover 10 of the mouse device 1 is no longer depressed by the user, in response to the restoring forces of the two springs 13, the upper cover 10 is returned to its original position where the upper cover 10 has not been depressed.
From the above discussions about the conventional key-free mouse device 1, the upper cover 10 is rotatable relative to the lower cover 11 by means of the two pivotal shafts 101 and the two fastening slots 111. Consequently, the first switch 14 or the second switch 15 on the circuit board 12 is correspondingly triggered.
However, the conventional key-free mouse device 1 still has some drawbacks. For example, after the upper cover 10 and the lower cover 11 are combined together, the upper cover 10 and the lower cover 11 are not completely sealed. Moreover, the circuit board 12 is disposed on the lower cover 11. When the upper cover 10 is rotated in a direction toward the left side or the right side and tilted, a vacant space between the upper cover 10 and the lower cover 11 is possibly too large. Consequently, the dust or other foreign matters may be introduced into the conventional key-free mouse device 1 through the vacant space. Under this circumstance, the circuit board 12 of the mouse device 1 and the electronic components on the circuit board 12 are possibly suffered from damage or malfunction, and the use life of the mouse device 1 is shortened.
Moreover, since the two springs 13 are respectively disposed on the first switch 14 and the second switch 15, the user's fingers have to be placed on the upper cover 10 at the positions corresponding to the first switch 14 and the second switch 15. In addition, the forces exerted on the first switch 14 and the second switch 15 should be large enough in order to trigger the first switch 14 and the second switch 15. Under this circumstance, the tactile feel is strengthened. As known, the strengthened tactile feel is detrimental to hand care.
Moreover, the user usually holds the sidewall of the mouse device in order to move the mouse device or perform any other appropriate operation. Since the sidewall of the mouse device 1 is extended from the upper cover 10, the user fails to stably hold the sidewall of the mouse device 1 during operation of the mouse device 1. Moreover, during the process of moving the mouse device 1, the upper cover 10 is possibly pushed by the user. Under this circumstance, the first switch 14 or the second switch 15 may be erroneously triggered.
Therefore, there is a need of providing an improved key-free mouse device in order to eliminate the above drawbacks of the conventional key-free mouse device.